This invention relates to a system for scanning a document, which is positioned on a flat document support, and generating electrical signals representing the image information contained within the scanned areas of the document. The invention relates more particularly to systems for scanning a flat document surface and generating a series of electrical signals which are suitable for controlling an ink jet printer or other electrically operated dot matrix recorder. One such prior art system is disclosed in Paranjpe et al U.S. Pat. No. 4,112,469.
The scanning system disclosed in Paranjpe et al is particularly suitable for use in an ink jet office copier. In the system as disclosed there are a group of photocells which observe a series of points along a relatively short scan line. The system utilizes an interlacing scan technique and produces a copy in about one second. A rotating mirror is provided for scanning the document in one direction. Scanning in the transverse direction is provided by mounting the optical system on a movable table.
While the system as taught by Paranjpe et al is suitable as an office copier, it has inherent speed limitations which restrict its adaptability to higher speed applications. Such higher speed applications include the duplicating field, wherein two or more copies per second may be required. Heretofore there has been no scanning system capable of scanning a flat document at such speeds and producing scanning signals suitable for controlling an electrically operated dot matrix recorder.